We do our best to develop content that is going to work well for districts regardless of the LMS selected. Aside from Moodle I'm working primarily with districts using Canvas, Schoology, Google Classroom and a couple others. Here's how we make sure that what we create works for everyone...
We develop pretty much all of our content in Google Drive (you could just as easily do it in HTML pages) and then embed those (published) pages into iframes in Moodle Pages, Assignments, whatever. I set the width to 95% and the height to accommodate all of the content on the resource. (You can also embed the Share link this way to keep your formatting it just comes with the Google Doc toolbar.)
To the end user it looks like text on the page in the LMS. When I back up the course and restore it into another LMS we don't have to worry about any of the content not coming over (stick to Pages, Assignments, Forums and Quizzes). Some LMS allow Moodle backup files (Canvas, Schoology), some will need the IMSCC backup files.
Either way, any edits to the content made in Drive automatically populate in all copies of the course that exist. If a user wants to make any changes they simply duplicate the page and do with it what they'd like. It does not affect the original.
It works pretty well for most of our purposes. I'd still rather everything be in Moodle to take advantage of things like the Lesson module, auto-linking, Glossaries and completion tracking, but some people made a decision to go with something with less features and this process accommodates those platforms.
In another post I can share why I still think that this same instructional content would be far superior if it is completely self-contained in a Moodle environment. We're currently working with over 180 school districts in the state and this is what has worked best so far.